LEAVEN = THE SINS OF THE CORINTHIANS

1 Corinthians 5:1 It is reported commonly that there is fornication among you, and such fornication as is not so much as named among the Gentiles, that one should have his father's wife.

2 Corinthians 12:20 For I fear, lest, when I come, I shall not find you such as I would, and that I shall be found unto you such as ye would not: lest there be debates, envyings, wraths, strifes, backbitings, whisperings, swellings, tumults:

2 Corinthians 12:21 And lest, when I come again, my God will humble me among you, and that I shall bewail many which have sinned already, and have not repented of the uncleanness and fornication and lasciviousness which they have committed.